I am not familiar with the Doulton Ultracarb OBE filter. I believe it just has a granular activated carbon block. Where Aquaceras CeraMetix uses coconut shell carbon, and Aquaceras AquaMetix blends of filtering media.1 Yes, the ceramic can be scrubbed when the flow slows from sediment. 2 Yes, it has a slower flow as it is an AquaMetix/carbon block with a ceramic shell

This is a block filter, so the water passes through the sides of the filter, not through the hole at the top. So both holes are sealed. Just make sure both washers are on each end, and it seals the ends when you tighten the canister onto the base of the housing, so the water has to go through the filter's sides. With the granular filter you had before, water flows through the top of the filter, down through the filtering media, and out so the top of the filter had to be open.

No, it does not open on either end. It is a replacement filter it goes in your filter system.

Yes, it is compatible.

I am not familiar with the Alexapure under-sink filter, but if it is a standard 10" housing, then it will fit.

Yes, it should fit, as it appears to be a standard 10-inch housing.

You only need to clean it when the water flow slows way down.

Yes, it will fit We have lots of customers using these now that the ProMax filter has been discontinued.

Yes, you can use a soft brush or a Scotch-Brite green pad and scrub it under running cold water.

I am not sure of that item number, but it will fit in the ProOne ProMax and Cold Stream countertop and under-sink filter systems. They should be replaced annually.

Filters should be replaced annually or at a capacity of 1,400 gallons, whichever comes first

No, here is the link to that one.Aquacera AquaMetix Block Replacement Filter

Yes, you should still replace it yearly.

Yes, this one will fit in your system it is actually better than the Imperial Sterasyl as that is just a ceramic shell where this one has that and media inside to filter a wide range of other contaminants.

This fits into a standard 10' housing. so they are 2.5 X 10 inches. Yes it does filter out odors

We recommend 1,000 gallons or yearly, which ever comes first.

All of the ceramic filters we offer will filter naegleria fowleri. You can also use a UV Light. Naegleria fowleri infects people when water containing the ameba enters the body through the nose. Infection is rare and typically occurs when people go swimming or diving in warm freshwater places, like lakes and rivers. Very rarely, infections have been reported when people submerge their heads, cleanse their noses during religious practices, or irrigate their sinuses (nose) using contaminated tap or faucet water. Here are a couple links for more infoTap & Faucet WaterPrevention & Control